[SPARK-2558][DOCS] Add spark.yarn.queue description to YARN doc

Put original YARN queue spark-submit arg description in
running-on-yarn html table and example command line
This config is only supported in yarn client mode right now.  Its more because of backwards compatibility and being able to pass it around in client mode then anything. In general you can use the spark-submit --queue option. If we want to make it available as a config then we should make it available in both modes. 

So I would prefer to leave this config undocumented and tell people to use the --queue option until support for both modes is added.